Rotary deflection separator



` Aug. 31; 1943- E. T. LxNDERoTH ROTARY DEFLECTION SEPARATOR OriginalFiled Dec. l5, 1938 3 Sheets-Sheet 1 Aug' 31, 1943- T. LINDEROTH2,328,220

ROTARY DEFLECTION SEPARATOR Oiginal Filed DeC. 15, 1938 3 Sheets-Sheet 2Alllg- 31, 1943. E. T. LINDEROTH 2,328,220

`ROTARY DEFLECTION S EPARATOR Original Filed Dec. l5, 1938 5Sheets-Sheet 5 Zn man;

Patented Aug. 31,

Erikrorvaia mnaeroui, Enkoping, sweden Original application December 15,1938, Serial No.

245,990. Divided and this application December 9, 1939, Serial No.308,493. In Sweden December 1 8. 1937 5 claims. (ci. 18s- 77) Thepresent invention relates to rotary deflection separators for treatingair and gases and for the removal of the finest and lightest par ticles,such as dust in air, flue gas particles and the like, and that at` thesame time the separator elements are of such a design that the danger ofclogging is removed. n

The separator, according to the invention, is based on the aerodynamicprinciple for removal of fine particles which is thoroughly explained inmy co-pending patent application No. 245,990 of Dec. 15, 1938, of whichthis application is a division which principle is based on the fact thatthe air or gas to be treated is directed against the separator surfaceat such a smal1 oblique angle and at such a velocity in relation to theseparator surface that the solid particles that enter the 4openings ofthe separator element are thrown againstthe walls .of said openings atpoints that are situated in front of or outside the aerodynamic stayingpoint so that the solid particles that are thus `arrested bytheseparator surface are thrown back by aerodynamic action and then caughtby and removed from the separator surface by an air or gas current,which may be a portion of the original air or gas current directedagainst the separator surface.

In case of a rotating cylindrical separator surface, the velocity of owof the air or gas relative to the separator surface is the resultant ofthe velocity of the air or gas and the peripheral velocity of theseparator surface, and therefore, the latter velocity is selected sohigh that said resultant velocity forms the necessary small obliqueangle relatively to the separator surface.

The particles that by aerodynamic action of the separator are preventedfrom passing therethrough tend to accumulate on or close to theseparator surface and would therefore after a short time interfere withthe functioning of the separator by reducing the aerodynamic forces sothat the particles would begin to penetrate the separator surface. Toprevent this, the particles must be removed as fast as they accumulate.

A primary object of the present invention is to provide in rotarydeflection separators an eilicient device for removing the accumulatingparticles, and said device according to the invention includes adischarge conduit for carrying away the solid separated particlesaccumulating on or adjacent the rotating separator surface provided withan inlet opening extending along the whole active separator surface inthe axial direction of the latter and situated close to the separatorsurface, said inlet opening being combined with a device for blowing orsucking the accumulating particles into said inlet opening by means of agas or air current.

'Ihe device for blowing or sucking the accumu- Y lating particles intosaid inlet opening may for instance be adapted to blow the particles bymeans of a portion of the untreated gas or air current driven againstthe separator surface, in which case said device may consist of a curvedchannel arranged peripherally along the separator surface, which channelis connected to said inlet opening and adapted to lead the scavenginggas or air'current along the separator surface.

According to another embodiment, the device for blowing the accumulatingparticles into said inlet opening consists of a channel opening close tothe separator surface on the side opposite to said inlet opening andadapted to direct a scavenging gas or air current through the separatorsurface into said inlet opening.

A number of embodiments of a rotary deflection separator according tothe invention are diagrammatically illustrated on the accompanyingdrawings.

Fig. 1 is an axial section through one of the embodiments, and Fig. 2 isa cross-section taken along the line IIII in Fig. 1.

Fig. 3 is a cross-section through a second embodiment, and Fig. 4 anaxial section taken along the line IV-IV in Fig. 3.

Fig. 5 is a cross-section of a third embodiment taken on the line V-V inFig. 6, and Fig. 6 shows an axial section through the same.

Figs. 7 and 8 are sections through two diilerent embodiments of theseparator surface.

In Figs. l and 2, I designates the surface of the rotary cylindricaldeflection separator element provided with filter openings for thepassage of the gas or air current. The surface may consist of metal wirecloth or perforated sheet metal. When using metal wire cloth aspecial-woven wire cloth may be used, which substantially consists ofweft 4wires and which does not contain more warp wires than is necessaryto hold the weft wires together. The cloth may then be formed as acylinder in such a manner that the weft wires extend axially.

A suitable embodiment of thesurface consists of a special-madeperforated plate in which the bars between the holes are shaped in themanner shown in Fig. 7. rIhe rotor may alternatively be composed ofplates according to Fig. 8, the plates being so turned in relation tothe direction of rotation that the motion relative to the air will be asindicated by the arrow in Fig. 8.

Owing to the scale on which the parts in Figs. 1 to 6 are shown, theexact form of the surface I is not apparent but the specic details may,as will be understood, be in accordance with those shown in Figs. 7 or8.

The cylindrical surface I is at its one end attachedto a disc 2, whichis secured on the rotary drive shaft 3, while the other end of thesurface is secured to a ring 4. This ring is by means of a number ofbracing rods 5 connected to a disc 6 mounted on the shaft 3. If thesurface consists of wire cloth, it may be stretched, as the disc 6 ismounted on a sleeve 1a that is screwed onto the shaft 3 so that the discl5 may be displaced by turning the sleeve 1a. By means nof the braces 5the axial wires in the surface I may be stretched. ,This is a greatadvantage as it has proved to be difficult to weave the cloth materialso that the weft wires are absolutely straight. The axial stretching ofthe cloth entails also the advantage that the wire cloth cy]- inder will-be as evenly round as possible.

The rotary deflection separator is at the same time adapted to propelthe gas or air current to be ltered. For this purpose the channel I,through which the gas or air is admitted, is formed 'as a spiral-shapedchannel surrounding the surface I. The channel 1 is connected to aninlet 8 having a gradually decreasing cross-sec tional area in thedirection of the flow. The channel 'I has a cross-sectional area whichgradually diminishes in the direction of flow of the air orgas current,which is the same as the direction of rotation of the surface I. The airor gas is thus led through the channel 'I around the cylinder in thedirection of rotation of the l latter at the same time as the air or gasis directed into the cylinder from without. Due to the increasedvelocity which the air obtains in the inlet spiral I before the entranceinto the separator cylinder, the losses due to impact of the airagainstrthe cylinder are reduced. The treated air or gas then flows asindicated by arrows in Fig. 1 into a second spiral shaped outlet channel9, which is arranged at the open side of the drum so that itcommunicates with the interior of the latter. 'I'he flow area of thechannel 9 widens gradually in the direction of rotation of the surfaceI, and its wide end portion is connected to an outlet I adapted as adiffuser, whereby the kinetic energy ofthe air is transformed intopressure energy.

The dust that is prevented from passing through the deflection separatortends to accumulate on or close to the surface I and is removed by thefollowing means.

A discharge conduit for the accumulating particles is shownat II. Tothis discharge conduit l an inlet opening I2 is connected, which inletopening is arranged close to the surface I and is suitably slot-shapedand extended along the entire active separator surface in the axialdirection of the latter, andadapted to cooperatewith a channel I3 thatconveys a scavenging air or gas current along the surface .into theinlet open- (ing I2 bringing along the solid particles. In Figs. 1 and2, the channel I3 consists of the narrowest portion of thespiral-channel 1, :and the scavenging air is thus a portion of theuntreated air current directed towards the separator. After removal ofthe dust, the air current led off through the conduit II maybe returnedto the main untreated air current at some convenient place in the supplyconduit.

The inlet opening I2 is connected to the discharge conduit Il by meansof a tube I4 widening as a diffuser so thatI a suction effect isproduced whereby the removal of the particles is facilitated.

A condition for the ne dust really'being sucked away is, however, thatthe inlet opening I2 is 10 arranged in immediate vicinity of theseparator cylinder with the least possible clearance.

In the embodiment according to Figs. 3 and 4. one end of the separatorcylinder I5 provided with openings is secured to a disc I1 mounted onthe rotary shaft I6, while the other end of the cylinder is stiffened bya ring I8. The air or gas to be treated is admitted centrally throughthe channel I9 into the interior of the cylinder, is then passed throughthe cylinder and thrown out into a channel 20 which is spiral-shapedarranged around the cylinder and'having an area increasing in thedirection of rotation of the cylinder I5. The channel 20 is connected toan outlet 2|. To remove the separated particles accumulating close tothe interior surface of the cylinder, a discharge conduit 23a isprovided, which conduit is connected to a suitably slotformed inletopening 22, which is arranged close to the separator surface and isextended along the entire active separator surface in the axialdirection of the latter. The opening 22 is suitably connected to theconduit 23a by means of a tube 23 adapted as a diffuser. On the oppositeside of the separator surface in relation to the inlet opening 22 achannel 24 is provided, which channel opens close to the separatorsurface opposite the inlet opening 22 and isadapted to direct a.scavenging gas orair current through the separator surface into theinlet opening 22 so that the particles are removed. The channel 24 mayfor example as shownbe formed as a diffuser so that the scavengingcurrent obtains over-pressure. The channel -24 is in otherwords-arranged on the pressure side of the separator while the diffuserchannel 23 simultaneously effects a sucking action. This embodiment ispreferably intended for the separation of lighter particles such as dustin air.

In the embodiment according to Figs. 5 andv 6, the separator cylinder 25.provided with filter openings is attached to the disc 26 secured to theshafts of the motor 21. The illter is mounted inside a housing 28, andthe gas or air is admitted through a cylindrical protecting grate 29.

'The housing 28 is provided with a central outlet 30 for the treated gasor air. The. gas or air is thus admitted radially from the outside allaround the whole separator surface. A rim of stationary guide vanes 3|are providedinside the cylinder. The ends of the vanes turned towardsthe cylinder 25 form a small angle with the tangent of the cylindersurface at a point where an extension of the vane edge would intersectthe cylinder. 'I'he curvature of the vanes is small nearest to thecylinder but increases inwards so that the interior ends of the vanesterminate substantially in a radial direction. Between adjacent vanes achannel 32' formed,^which channel widens in the direction of flow of thetreated air. Provided that the widening of said channel is not toogreat, the channels 32 will act as diifusers sol that the pressure isincreased in the direction of now. By giving suitable-dimensions andshape.l to the venes, said increase oi'4 pressure may be greater thanthe total resistance to flow through the system, whereby a separate fanfor driving the air current through the separator will be unnecessary.It is even possible to obtain such a high overpressure inside the vanerim that the resistance-to :dow in a pipe conduit, through which thetreated airis led to the place of consumption, is overcome. Y

A condition for such'propelling. includes the feature that the vaneangle does not exceed and that the first portion of said intermediatechannels 32 nearest to the inlet edge is not widened a, greater anglethan at the most for a distance corresponding to a relation of wideningof 2:1 of the cross-sectional area of the channel. If it is notsufficient that the apparatus is blown clean but that also the greatestpossible static pressure head is to be obtained, it is suitable to useat the most half as large angles.

For scavenging the separator surface free from accumulating particles,an inlet opening for the particles leading to a discharge conduit 33 bywayof a, diffuser channel 34 is provided close t0 the separator surfaceon the outside of the latter. 'I'he opening 35 extends in the axialdirection along the whole active width of the separator surface.Opposite the opening 35 and on the inside of the separator surface a.screen 35 -is provided close to the separator surface. screen 36 extendsalong the whole width of the separator surface so that a channel 31 isformed, by means of which a portion of the air or gas is returnedthrough the separator surface into the inlet opening 35 toh sweep awaythe particles. Alternatively or together with the screen 35 the openingof a guide vane channel 32 situated right opposite the inlet opening 35may be shaped as a scavenging air channel 38 as indicated in Fig. 5. Dueto the over-pressure inside the guide vane rim and the suction effect ofthe diffuser channel 34 the air is pressed back through the channel 38and through the separator into the inlet opening 35 and scavenges theseparator surface clean.

Having now particularly described the nature of my invention and themanner of its operation what I claim is:

1. A rotary deflection separator for a gaseous medium comprising, ahousing, a rotor mounted within said housing having a surface providedwith gas flow impelling means and openings for the medium, means forrotating said surface at a, high peripheral velocity, means for leadinga current of the medium to be treated against one side of the rotatingsurface, a diiuser channel arrangement communicating with the oppositeside of the rotating surface to receive the filtered medium and adaptedto assist in creating a drop in static pressure between the oppositesides of the 4said surface and to transformkinetic energy of the mediumafter passing through the rotating surface into pressure energy forfurther transport of the treated medium, a discharge conduit on theinlet side of the surface for carrying away the separated solidparticles accumulating close tc the rotating surface, said dischargeconduit being provided with an inlet opening for said solid mattersituated close to the surface, and means for directing a jet ofscavenging gaseous medium to blow said solid particles into said inletopening.

2. A rotary deflection separator for a gaseous medium comprising, ahousing, a rotor mounted Within said housing having a cylindricalsurface provided with gas flow impelling means and openings for themedium, means for rotating said cylinder at a high peripheral velocity,a spiralshaped inlet channel surrounding said cylinder and leading acurrent of the medium to be filtered about and through the cylindricalsurface, said channel having a` gradually diminishing crosssectionalarea in the direction of flow and in the direction of rotation of thecylinder, a dinuser channel arrangement communicating with the inside ofthe cylinder to receive the treated medium and adapted to assist increating a drop in static pressure between the opposite sides of thesurface and to transform kinetic energy of the medium after passingthrough the rotating surface into pressure energy for further transportof the medium, a discharge conduit on the outside of the cylinder forcarrying away the separated solid particles accumulating close to therotating surface, said discharge conduit being provided with an inletopening for said solid The CAD

matter situated close to the surface and communicating with thenarrowest portion of said spiral-shaped inlet channel so that a portionof the originally admitted gaseous medium current will as a jet blowsaidsolid particles into said inlet opening.

3. A rotary deflection separator for a gaseous medium comprising, ahousing, a rotor mounted within said housing having` a cylindricalsurface provided with gas flow impelling means and openings for themedium, means for rotating said cylinder at a high peripheral velocity,a spiral shaped inlet channel surrounding said cylinder and leading acurrent of the medium to be treated about and through the cylindrical Fsurface, said channel having a gradually diminishing cross-sectionalarea in the direction of flow and in the direction of rotation of thecylinder, a spiral-shaped outlet channelA for the treated mediumcommunicating with the interior of the cylinder and located at an openside of the latter and having a cross-sectional area which graduallyincreases in size in the direction of rotation of the cylinder andterminates with a Widening diffuser pipe, the latter spiral-shapedchannel and diiuser being adapted to assist in creating a drop in staticpressure between the opposite sides of the surface and to transformkinetic energy of the treated medium into pressure energy for furthertransport of the same, a discharge conduit on the outside ofI thecylinder for carrying away the separated solid particles accumulatingclose to the rotating surface, said discharge conduit being providedwith an inlet opening for said solid matter situated close to thesurface and communicating with the narrowest portion of saidspiral-shaped inlet channel so that a portion of the originally admittedmedium current will as a jet blow said solid particles into said inletopening.

4. A rotary deflection separator for a gaseous medium comprising, ahousing, a rotor mounted within said housing having a cylindricalsurface provided with gas flow impelling means and openings for themedium, means for rotating said cylinder at a high peripheral velocity,means for leading a current of the gaseous medium to be treated againstthe inside of the rotating cylinder, a `spiral-shaped outlet channel forthe treated medium surrounding the cylinder and having a cross-sectionalarea which increases in siz in the direction of rotation of the cylinderand is terminated by a widening diffuser pipe, said channel and diffuserarrangement being adapted to assist in creating a drop in staticpressure between the vopposite sides of the surface andto transform'kinetic energy of the treated medium into pressure energy for furthertransport `of the same. a discharge conduit on the inside of thecylinder for carrying away the separated solid particles accumulatingclose to the rotating surface, said discharge conduit being providedwith an inlet opening for said solid matter situated close to thesurface, a channel leading from the aforesaid diiuser pipe on theoutside of the cylinder .to a point opposite said inlet opening andbeing adapted to blow a jet of scavenging air from the diffuser andthrough the rotating surface into said inlet opening to sweep away saidSolid matter.

5. A rotary deflection separator for a gaseous medium, a rotor mountedwithin said housing having a cylindrical surface provided with gas flowimpelling means and openings for the medium, means for rotating saidcylinder at a high peripheral velocity, the outside of the cylinderbeing adapted as inlet side for a current ofthe medium to be treated, arim of stationary guide vanes mounted inside the cylinder so shaped asto form all around the inside of the cylinder a plurality of outletchannels for the treated me- Adium which widen as diiusers in thedirection inwards and are provided with inlet portions being obliquelydirected towards the interior 5 periphery of the cylinder in thedirection opposite the direction of rotation of the latter so that thediffuser channels assist in creating a drop in static pressure betweenthe opposite sides of the surface and transform kinetic energy of thegase- 10 ous medium current after passing through the surface intopressure energy for the further transport of the treated medium, adischarge conduit on the outside of the cylinder for carrying away theseparated solid particles accumulat- 15 ing close to the rotatingsurface, said discharge being provided with an inlet opening lfor saidsolid matter situated close to the surface, a channel arranged on theinside of the surface adapted to lead a current of scavenging air from adiffuser 20 channel to a point close to the surface and oppo-

